Fluid mixing apparatus



y 4, 1956 H. ESCHER 2,755,75G

' FLUID MIXING APPARATUS Filed March 28. 1952 2 Sheets-Sheet 1 In van 790; 5& a m

July 24, 1956 H. ESCHER 2,755,750

FLUID MIXING APPARATUS Filed March 28. 1952 2 Sheets-Sheet 2 In vemv nited States Patent FLUID MIXING APPARATUS Hans Escher, Wollongong, New South Wales, Australia, assignor to Australian Iron & Steel Limited, Sydney, New South Wales, Australia Application March 28, 1952, Serial No. 279,137 Claims priority, application Australia January 4, 1952 2 Claims. (Cl. 110-22) This invention relates to an improved apparatus for mixing fluids.

The object of the invention is to provide an apparatus for mixing fluids which results in intensive mixing with a minimum of energy dissipation.

It is also an object of the invention to provide apparatus of relatively simple construction.

Apparatus in accordance with the present invention comprises an assembly of a plurality of whirlers, each whirler being so arranged that in at least a majority of cases the stream of fluid issuing therefrom rotates in a direction opposite to the direction of rotation of the adjacent stream and the contacting boundary layers move in the same direction.

Each whirler consists of a number of fixed blades held in a suitable frame the blades being helical somewhat like the blades of a screw propeller or air screw so that a rotary motion is imparted to fluid flowing over the surface of the blades.

The invention will be better understood by reference to the following description of two specific embodiments of the invention, which are shown more or less schematically in the accompanying drawings, in which:

Fig. 1 represents a sectional elevation on line 1-1 of Fig. 2 of a gas burner constructed and operating in accordance with the invention;

Fig. 2 represents a front end sectional view on line 22 of Fig. 1 of the gas burner; and

Fig. 3 represents an elevation partly in section of a modified gas burner constructed and operating in accordance with the invention.

Referring to the gas burner arrangement shown in Figs. 3 and 4 the main gas supply enters through pipe 11 and the air supply through pipe 12. A number of pipes 13 provided at their outlets with whirlers 14 is attached to a plate 15 forming a partition between the air and fuel gas space of the burner. The whirlers 14 are of similar construction to the whirlers 6 described above, the outer ends of the blades being secured to the wall of tubes 13, while the inner ends of the blades are secured to a central boss. The fuel gas flows into the casing 16 surrounding tubes 13 and in between the tubes 13 and then through openings 17 into the combustion chamber 18. The air streams enter the combustion chamber at substantially the same point through whirlers 14, the vanes or blades of which are so arranged that the air stream issuing from each whirler rotates in a direction opposite to the direction of rotation of the adjacent stream, with the contacting boundary layers moving in the same direction (see Fig. 2). This results in a pumping action which moves Patented July 24, 1956 the gas from the outer space 19 to the inner space 20 and vice versa giving intimate mixing of air, fuel gas and burnt gases in the combustion chamber 18, thereby increasing the efficiency of the burner.

If desired, an additional or alternative fuel may be introduced through pipe 21 the outlet end of which may be provided with whirlers 22.

The gas burner arrangement shown in Figs. 1 and 2 may be modified as shown in Fig. 3 by the provision of additional fuel pipes 23 positioned within the air supply pipes 13 with the front ends projecting through the centre of whirlers 14 and the rear ends connected to an annular header 24 provided with a tangential feed (not shown). Solid fuel, such as pulversised coal, or the like, is fed into the pipes 23 through header 24. The rotary motion of the air issuing from the whirlers 14 in the pipes 13 causes intensive and intimate mixing of the pulverised fuel with the gas issuing from openings 17 and the air thus assuring efiicient combustion of gaseous and solid fuel. The front ends of pipes 23 may be provided with cone spreaders or the interior of the pipes may be rifled so as to assist in the breaking up of the pulverised fuel as it emerges from the pipes 23. By reducing the diameter of pipes 23 the pulverised fuel may be replaced by fuel oil if desired.

The burner construction described above is particularly suitable for burning a variety of fuels simultaneously. For example, blast furnace gas may be fed in through pipe 11, coke oven gas through pipe 21 and pulverised coal through pipes 23 thus making maximum use of fuel from the various sources.

It will be evident from the simple nature of the apparatus described above that existing equipment can be readily converted to operate in accordance with the present process.

While the invention has been described with reference to a heat exchanger unit and a gas burner it may be readily applied to other constructions in which it is desired to secure intensive mixing with a minimum of energy dissipation.

I claim:

1. Gas burner apparatus comprising a combustion chamber, a gas inlet tube, a central fuel inlet tube in said gas inlet tube, a plurality of air inlet tubes arranged within said gas inlet tube in a circular pattern around said central fuel inlet tube, the outlet ends of each of said tubes being connected to a combustion chamber, whirlers provided in the outlet end of each air inlet tube and the central fuel inlet tube, said whirlers being constructed and arranged so that in at least a majority of cases the stream of air issuing from one whirler rotates in a direction opposite to the direction of rotation of the adjacent air streams and the adjacent boundary layers move in the same direction and the general axial direction of the air streams is the same as that of the gas stream.

2. Gas burner apparatus comprising a combustion chamber, a gas inlet tube, a plurality of air inlet tubes arranged within said gas inlet tube in a circular pattern, the outlet ends of the air inlet tubes and the gas inlet tube being connected to said combustion chamber, a whirler in the outlet end of each air inlet tube, said whirlers being constructed and arranged so that in at least a majority of cases the stream of air issuing from one whirler rotates in a direction opposite to the direction of rotation of the adjacent air stream and the adjacent boundary layers move in the same direction and the general axial direction of the air streams is the same as that of the gas stream, each whirler having an opening at its center, and a fuel inlet pipe for solid fuel positioned within each air inlet tube projecting into the combustion chamber through the opening in the center of the Whirler positioned in the outlet end of the respective air inlet pipe.

1,418,877 Mabee June 6, 1922 4 Reeves Mar. 13, Joubert Aug. 26, Seymour July 31, Chase May 24, Burg Jan. 16, Moyer Aug. 5, Hanzalek July 10,

FOREIGN PATENTS Great Britain of France Apr. 8, 

